Six imams who are suing an airline and an airport for removing them from a flight also have aimed the lawsuit at passengers who the imams believe reported some of their activities.

The suit filed this week in U.S. District Court in Minneapolis names as defendants “John Does” who “contacted US Airways to report the alleged suspicious behavior” of the imams before the Nov. 20 flight — an inclusion some lawyers, who are not connected to the litigation, say will have a “chilling effect” on airline security.

“If such a suit could proceed, it would have a chilling effect on the willingness of people to provide information that authorities need to act when people are engaged in wrongdoing,” said Mark Behrens, a liability defense lawyer with the Washington firm of Shook, Hardy & Bacon.

“If reporting suspicious behavior becomes actionable, that could have a dangerous precedent for reporting other crimes, like child abuse and abductions,” Mr. Behrens said. “It’s certainly a form of intimidation to go after passengers.”

The lawsuit primarily targets US Airways and the Minneapolis-St. Paul Metropolitan Airports Commission, but suing passengers who report suspicious behavior “sends a terrible message if we are at all concerned about the threat of terrorism,” said Walter Olson, a senior fellow at the Manhattan Institute and author of several books on litigation in the U.S.

“The implications are that if you appear to just buzz about what you perceive to be a security threat then you are a legal wrongdoer and responsible for damages, even if all you did was notify the authorities. And that would have a tremendous chilling effect, win or lose.

“Unless this is thrown out of court early, the lesson learned will be that next time someone sees something, it may be safer to stay quiet and hope someone else reports it. Even if the charges get thrown out or dropped, this is an announcement that you could be caught up in litigation for years and spending your savings on lawyers.”

The lawsuit sets out that “plaintiffs are unaware of the true names and capacities of defendants sued herein as John Does and therefore sue said defendants by such fictitious names. Plaintiffs will seek leave to amend this complaint to allege true names, capacities, and circumstances supporting the liability of said defendants at such time as plaintiffs ascertain the same.”

Three of the imams said they “noticed an older couple was sitting behind them and purposely turning around to watch the other plaintiffs as they prayed together” and that the man “picked up his cellular phone and made a phone call while watching the plaintiffs pray.”

“Defendant John Doe moved to a corner near Gate C9. While observing the plaintiffs discreetly, he kept talking into his cellular phone,” the lawsuit sets out.

The plaintiffs’ lawyer, Omar Mohammedi, declined to comment except to say they are not naming passengers at this time.

“Once you have discovery or find out what happened, then we will name them, then you will know who these people are,” he said. “I’m not saying passengers, not saying employees or anything at this point. It is our decision at some point if we have enough grounds or evidence to go after them, or whether there is not enough grounds.”

The imams’ prayer was reported by the gate agent, who told police “I was suspicious by the way they were praying very loud.” Another flight attendant said she noticed three to four people praying but did not consider it unusual.

One passenger said the men were near the ticket counter and “seemed angry,” and engaged in a “heated discussion” about the U.S. “killing Saddam” Hussein, and then shouting “Allah, Allah, Allah” when called for boarding.

Passengers and the flight crew say the men were disruptive and did not take their assigned seats and formed a pattern similar to the September 11 hijackers. Some of the men asked for seat-belt extensions they did not need, criticized the war in Iraq and President Bush, and talked about al Qaeda and Osama bin Laden.

The men were escorted off Flight 300 to Phoenix, handcuffed briefly, then searched and questioned for several hours by airport police and members of the Joint Terrorism Task Force.

The lawsuit does not address the actual claims made by passengers and the flight crew in reports filed by law-enforcement officers, except for the request of seat-belt extenders. The questions presented in the lawsuit reflect specific charges of each man’s behavior reported by passengers and the flight crew.

The imams who filed the lawsuit are Omar Shahin, Ahmed Shqeirat, Didmar Faja, Mahmoud Sulaiman and Marwan Sadeddin of Arizona, and Mohamed Ibrahim of California.

The lawsuit says each man was asked separately whether they liked President Bush and whether they “would like the president to be harmed,” and all responded no.

Mr. Shqeirat was asked “questions about his background including where he was from, his Social Security number, address and whether he did anything out of the ordinary at the airport.” He was further asked “whether he moved from his seat,” the lawsuit said.

Mr. Shahin was asked “about his background and inquired into his national origin, his citizenship and the school in which he taught in Jordan. They asked him about the conference he was attending in Minneapolis. The Secret Service asked Plaintiff Shahin whether he had discussed Saddam Hussein and Iraq while on the plane.

“The FBI asked Mr. Faja about himself, including his activities and the mosques to which he belonged.” The FBI asked Mr. Sadeddin if he was blind, based on the report by a flight attendant that he “pretended to be blind.”

The lawsuit further said: “The FBI read [Mr. Sadeddin] his rights and asked him about his life, activities, where he was born, where he prayed, where he lived in the Middle East and when he got his citizenship. They also asked him about his views on U.S. foreign policy and Saddam Hussein.

“The FBI and Secret Service repeated the same procedure with Plaintiffs Ibrahim and Sulaiman each time questioning them about their backgrounds and asking them whether they wanted to see the U.S. President harmed.”